Rubber mixture comprising biotechnically modified rubber particles

Abstract

A rubber mixture includes natural rubber, butadiene rubber, styrene-butadiene rubber, synthetic polyisoprene or ethylene-propylene-diene rubber or a blend of two or more types of rubber, filler, crosslinking system and recycled rubber particles. The recycled rubber particles may be biotechnologically modified. The addition of the modified rubber particles can improve the physical properties of rubber mixtures and the lifetime of engine mounts or bushings. The biotechnical processing of the vulcanized rubber and the use of the high-quality modified rubber particles in new mixtures can distinctly reduce the amount of waste and the amount of CO 2 emitted by virtue of the use of recyclate and can increase the proportion of recycled material in the product. The disclosure further provides for the use of rubber mixtures for industrial rubber products, such as engine mounts and bushings.

1 . A rubber mixture comprising:
 rubber selected from natural rubber, butadiene rubber, styrene-butadiene rubber, synthetic polyisoprene or ethylene-propylene-diene rubber or a blend of two or more types of rubber,   at least one filler,   at least one crosslinking system, and   recycled rubber particles,   wherein the recycled rubber particles consist of biotechnologically modified rubber mixtures and have a functionalized surface with functional groups.   
     
     
         2 . The rubber mixture as claimed in  claim 1 , wherein the biotechnologically modified rubber particles are enzyme-treated rubber particles based on vulcanized isoprene rubber. 
     
     
         3 . The rubber mixture as claimed in  claim 1 , wherein the rubber mixture contains 15 to 75 phr of biotechnologically modified rubber particles. 
     
     
         4 . The rubber mixture as claimed in  claim 1  claims, wherein the rubber mixture contains a minimum of 50 phr of biotechnologically modified rubber particles. 
     
     
         5 . The rubber mixture as claimed in  claim 1 , wherein the recycled rubber particles have an average particle diameter of less than 700 μm. 
     
     
         6 . The rubber mixture as claimed in  claim 1 , wherein the recycled rubber particles have an average particle diameter of less than 500 μm. 
     
     
         7 . The rubber mixture as claimed in  claim 1 , wherein the recycled rubber particles have an average particle diameter of less than 400 μm. 
     
     
         8 . The rubber mixture as claimed in  claim 1 , wherein the recycled rubber particles have an average particle diameter of less than 250 μm. 
     
     
         9 . The rubber mixture as claimed in  claim 1 , wherein the modified rubber mixtures have, as functional groups, carbonyl groups on a particle surface. 
     
     
         10 . The rubber mixture as claimed in  claim 9 , wherein the carbonyl groups are terminal aldehyde groups and/or terminal ketone groups. 
     
     
         11 . The rubber mixture as claimed in  claim 1 , wherein the rubber mixture comprises, as rubber, a mixture of natural rubber and synthetic polyisoprene. 
     
     
         12 . The rubber mixture as claimed in  claim 1 , wherein the filler is carbon black or silica. 
     
     
         13 . The rubber mixture as claimed in  claim 1 , wherein the crosslinking system is sulfur. 
     
     
         14 . The rubber mixture as claimed in  claim 13 , wherein the sulfur is present in an amount of 0.1 phr to 5 phr. 
     
     
         15 . The rubber mixture as claimed in  claim 1 , wherein the rubber mixture additionally comprises one or more of the following components: plasticizer, resin, aging stabilizer and accelerator. 
     
     
         16 . The rubber mixture as claimed in  claim 1 , wherein the rubber mixture comprises: 
       
         
           
                 
                 
               
                     
                 
                   100 phr 
                   natural rubber and/or synthetic polyisoprene, 
                 
                   15 phr to 75 phr 
                   modified rubber particles, 
                 
                   0.1 phr to 5 phr   
                   sulfur, 
                 
                    5 phr to 200 phr 
                   carbon black, preferably 10 phr to 150 phr carbon 
                 
                     
                   black, and 
                 
                    1 phr to 50 phr 
                   further additives. 
                 
                     
                 
             
                
               
               
                
                
                
                
                
                
                
               
            
           
         
       
     
     
         17 . The rubber mixture as claimed in  claim 1 , wherein the modified rubber particles are produced in a process comprising:
 a) providing rubber wastes composed of a mixture of natural rubber and synthetic polyisoprene or of natural rubber or of synthetic polyisoprene, each comprising carbon black, silica or other fillers,   b) grinding the rubber wastes to particles having an average particle diameter of less than 700 μm, of less than 500 μm, less than 400 μm, or less than 250 μm,   c) pretreating the rubber particles with an organic solvent in an extraction step, and   d) treating the rubber particles with an enzyme selected from Lcp, RoxA, RoxB, and mixtures thereof.   
     
     
         18 . A process for producing modified rubber particles as claimed in  claim 1 , comprising:
 a) providing rubber wastes composed of a mixture of natural rubber and synthetic polyisoprene or of natural rubber or of synthetic polyisoprene, each comprising carbon black, silica or other fillers,   b) grinding the rubber wastes to particles having an average particle diameter of less than 700 μm, less than 500 μm, less than 400 μm, and less than 250 μm,   c) pretreating the rubber particles with an organic solvent in an extraction step, and   d) treating the rubber particles with an enzyme selected from Lcp, RoxA, RoxB, and mixtures thereof.   
     
     
         19 . The use of rubber mixtures as claimed in  claim 1  for industrial rubber products. 
     
     
         20 . The use of rubber mixtures as claimed in  claim 1  for engine mounts and bushings.